View Full Version : Don't use a polarizer with a 35mm adapter.
Policar
04-03-2006, 02:52 PM
I don't know why but I get grain like super crazy. Anyone want to explain?
Are you using the polo in front of the 35mm lens, or on the DVX?
Policar
04-03-2006, 04:04 PM
Linear polarizer in front of the SLR lens, turned down to block glare/make the sky bluer.
Bill__Turner
04-03-2006, 04:05 PM
A polarizer absorbs almost 2 full stops of light (acts almost like ND 0.6) is it possible that this loss combined with the light loss of the adapter is causing the grain ( that is the problem is not enough light)?
Bill Turner
Schneider Optics
Century Division
Policar
04-03-2006, 04:36 PM
I was shooting direct sunlight at 3-4pm without a cloud in the sky. Without the adapter, I had to use ND 1/64 to get a correct exposure, although I forget the f-stop. There was tons of light.
The amount of grain was really remarkable--and it was most adapter-induced (static). I suppose the polarizer combined with the 85B combined with the f2.8 lens created it, but I thought static grain was based entirely on aperature and that ND filters, etc. wouldn't increase it, provided there was enough light to use them.
The grain was very bad. Weird.
It could be that the linear polarized light was reacting with the orientation of the GG (either the ground glass chips or perhaps the orientation of the polimers if you are using plastic?)
Perhaps a circular polo might not have this effect.
Policar
04-03-2006, 05:56 PM
It's a beta G35. 95% sure it's microwax (have I said too much?)
For the record I'm not 100% sure. Also, the final product will be great I'm convinced so don't take this a strike against it, seriously.
marlenedegrood
04-03-2006, 06:27 PM
I would love to see a comparison, with Polarizer and without.
ovjamaica
04-03-2006, 07:15 PM
Hope you didn't sign an NDA. But I'd be interested to see it too if you're allowed that liberty. Probably not, but hey, doesn't hurt to ask.
Policar
04-03-2006, 07:16 PM
I'd post it but my camera broke. Which means I'm out of hero fest 90% for sure. The same problem that kept me out of sci-fi fest except that movie wasn't going well in the first place. And this is after a $300 repair (which admittedly fixed another problem, too.)
It's not HORRIBLE, but it's not quite what I'd classify as useable. And I've shot f2.8 with it before and noticed either no grain or next to none.
marlenedegrood
04-03-2006, 07:53 PM
Wow....really sorry about your camera breaking......rotten luck. What's wrong with the camera?
Policar
04-03-2006, 08:20 PM
Dirt in the photo sensor or a torn cable. Last time it was that plus water in the iris wheel.
I don't get it. I take such good care of my camera. The tech was even like "wow you take such good care of this camera."
*sighs*
Anyhow, it should probably be a few hundred which just means a few more dozen hours at the old work study job. Oh well. Being a student sucks when it comes to the cash flow.
Noel Evans
04-04-2006, 06:32 AM
Hmm not sure why your getting added grain with a polarizer....... I recently posted some letus flip footage shot entirely with a ploarizer. Cant say I have extra grain on it. This of course is a web version so harder to tell, but full size I was getting the mimimal amoutn I guess possible with a 35mm adapter. http://www.dvxuser.com/V6/showthread.php?t=51371
As you can see I still managed to over expose part of a shot, which was shot away from the sun using ND 1/16th. This has no cc. Excuse the dirty lense, I cleaned it and seems got too close to some plants which in turn put bits on the front, you will see the two little nasties.
Sorry edited final note: this was using a circular Cokin polarizer.